We are given with
136 g P4
excess oxygen
The complete combustion reaction is
P4 + 5O2 => 2P2O5
Converting the amount of P4 to moles
136/123.9 = 1.098 moles
Using stoichiometry
moles P2O5 = 1.098 x 2 = 2.195 moles P2O5
Answer: It is important for an equation to be balanced because if it is not then the reactants won't match the products.
Explanation: I don't know if you will understand this but here:
Let's say you're cooking eggs, you're reactants so to speak would be 3 eggs and 1 tablespoon of oil so you put it together using heat and a pan. Your products have to match what you have in the beginning. You cannot have an equation that looks like this
Reactants = 3eggs + 1Tbsp oil ---pan/heat---> 6eggs + 1 cup of oil
You cannot get something from what you don't have. The number of how much of an element you have must be the same of both sides of the equation.
The mass is located in the necleus.
